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1 /*
2  * Copyright (C) 2012 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 #include <errno.h>
17 #include <string.h>
18 #include <stdint.h>
19 
20 #include <keystore/keystore.h>
21 
22 #include <hardware/hardware.h>
23 #include <hardware/keymaster.h>
24 
25 #include <openssl/evp.h>
26 #include <openssl/bio.h>
27 #include <openssl/rsa.h>
28 #include <openssl/err.h>
29 #include <openssl/x509.h>
30 
31 #include <UniquePtr.h>
32 
33 // For debugging
34 // #define LOG_NDEBUG 0
35 
36 #define LOG_TAG "OpenSSLKeyMaster"
37 #include <cutils/log.h>
38 
39 struct BIGNUM_Delete {
operator ()BIGNUM_Delete40     void operator()(BIGNUM* p) const {
41         BN_free(p);
42     }
43 };
44 typedef UniquePtr<BIGNUM, BIGNUM_Delete> Unique_BIGNUM;
45 
46 struct EVP_PKEY_Delete {
operator ()EVP_PKEY_Delete47     void operator()(EVP_PKEY* p) const {
48         EVP_PKEY_free(p);
49     }
50 };
51 typedef UniquePtr<EVP_PKEY, EVP_PKEY_Delete> Unique_EVP_PKEY;
52 
53 struct PKCS8_PRIV_KEY_INFO_Delete {
operator ()PKCS8_PRIV_KEY_INFO_Delete54     void operator()(PKCS8_PRIV_KEY_INFO* p) const {
55         PKCS8_PRIV_KEY_INFO_free(p);
56     }
57 };
58 typedef UniquePtr<PKCS8_PRIV_KEY_INFO, PKCS8_PRIV_KEY_INFO_Delete> Unique_PKCS8_PRIV_KEY_INFO;
59 
60 struct DSA_Delete {
operator ()DSA_Delete61     void operator()(DSA* p) const {
62         DSA_free(p);
63     }
64 };
65 typedef UniquePtr<DSA, DSA_Delete> Unique_DSA;
66 
67 struct EC_KEY_Delete {
operator ()EC_KEY_Delete68     void operator()(EC_KEY* p) const {
69         EC_KEY_free(p);
70     }
71 };
72 typedef UniquePtr<EC_KEY, EC_KEY_Delete> Unique_EC_KEY;
73 
74 struct EC_GROUP_Delete {
operator ()EC_GROUP_Delete75     void operator()(EC_GROUP* p) const {
76         EC_GROUP_free(p);
77     }
78 };
79 typedef UniquePtr<EC_GROUP, EC_GROUP_Delete> Unique_EC_GROUP;
80 
81 struct RSA_Delete {
operator ()RSA_Delete82     void operator()(RSA* p) const {
83         RSA_free(p);
84     }
85 };
86 typedef UniquePtr<RSA, RSA_Delete> Unique_RSA;
87 
88 struct Malloc_Free {
operator ()Malloc_Free89     void operator()(void* p) const {
90         free(p);
91     }
92 };
93 
94 typedef UniquePtr<keymaster_device_t> Unique_keymaster_device_t;
95 
96 /**
97  * Many OpenSSL APIs take ownership of an argument on success but
98  * don't free the argument on failure. This means we need to tell our
99  * scoped pointers when we've transferred ownership, without
100  * triggering a warning by not using the result of release().
101  */
102 template <typename T, typename Delete_T>
release_because_ownership_transferred(UniquePtr<T,Delete_T> & p)103 inline void release_because_ownership_transferred(UniquePtr<T, Delete_T>& p) {
104     T* val __attribute__((unused)) = p.release();
105 }
106 
107 /*
108  * Checks this thread's OpenSSL error queue and logs if
109  * necessary.
110  */
logOpenSSLError(const char * location)111 static void logOpenSSLError(const char* location) {
112     int error = ERR_get_error();
113 
114     if (error != 0) {
115         char message[256];
116         ERR_error_string_n(error, message, sizeof(message));
117         ALOGE("OpenSSL error in %s %d: %s", location, error, message);
118     }
119 
120     ERR_clear_error();
121     ERR_remove_state(0);
122 }
123 
wrap_key(EVP_PKEY * pkey,int type,uint8_t ** keyBlob,size_t * keyBlobLength)124 static int wrap_key(EVP_PKEY* pkey, int type, uint8_t** keyBlob, size_t* keyBlobLength) {
125     /*
126      * Find the length of each size. Public key is not needed anymore
127      * but must be kept for alignment purposes.
128      */
129     int publicLen = 0;
130     int privateLen = i2d_PrivateKey(pkey, NULL);
131 
132     if (privateLen <= 0) {
133         ALOGE("private key size was too big");
134         return -1;
135     }
136 
137     /* int type + int size + private key data + int size + public key data */
138     *keyBlobLength = get_softkey_header_size() + sizeof(type) + sizeof(publicLen) + privateLen +
139                      sizeof(privateLen) + publicLen;
140 
141     // derData will be returned to the caller, so allocate it with malloc.
142     UniquePtr<unsigned char, Malloc_Free> derData(
143         static_cast<unsigned char*>(malloc(*keyBlobLength)));
144     if (derData.get() == NULL) {
145         ALOGE("could not allocate memory for key blob");
146         return -1;
147     }
148     unsigned char* p = derData.get();
149 
150     /* Write the magic value for software keys. */
151     p = add_softkey_header(p, *keyBlobLength);
152 
153     /* Write key type to allocated buffer */
154     for (int i = sizeof(type) - 1; i >= 0; i--) {
155         *p++ = (type >> (8 * i)) & 0xFF;
156     }
157 
158     /* Write public key to allocated buffer */
159     for (int i = sizeof(publicLen) - 1; i >= 0; i--) {
160         *p++ = (publicLen >> (8 * i)) & 0xFF;
161     }
162 
163     /* Write private key to allocated buffer */
164     for (int i = sizeof(privateLen) - 1; i >= 0; i--) {
165         *p++ = (privateLen >> (8 * i)) & 0xFF;
166     }
167     if (i2d_PrivateKey(pkey, &p) != privateLen) {
168         logOpenSSLError("wrap_key");
169         return -1;
170     }
171 
172     *keyBlob = derData.release();
173 
174     return 0;
175 }
176 
unwrap_key(const uint8_t * keyBlob,const size_t keyBlobLength)177 static EVP_PKEY* unwrap_key(const uint8_t* keyBlob, const size_t keyBlobLength) {
178     long publicLen = 0;
179     long privateLen = 0;
180     const uint8_t* p = keyBlob;
181     const uint8_t* const end = keyBlob + keyBlobLength;
182 
183     if (keyBlob == NULL) {
184         ALOGE("supplied key blob was NULL");
185         return NULL;
186     }
187 
188     int type = 0;
189     if (keyBlobLength < (get_softkey_header_size() + sizeof(type) + sizeof(publicLen) + 1 +
190                          sizeof(privateLen) + 1)) {
191         ALOGE("key blob appears to be truncated");
192         return NULL;
193     }
194 
195     if (!is_softkey(p, keyBlobLength)) {
196         ALOGE("cannot read key; it was not made by this keymaster");
197         return NULL;
198     }
199     p += get_softkey_header_size();
200 
201     for (size_t i = 0; i < sizeof(type); i++) {
202         type = (type << 8) | *p++;
203     }
204 
205     for (size_t i = 0; i < sizeof(type); i++) {
206         publicLen = (publicLen << 8) | *p++;
207     }
208     if (p + publicLen > end) {
209         ALOGE("public key length encoding error: size=%ld, end=%td", publicLen, end - p);
210         return NULL;
211     }
212 
213     p += publicLen;
214     if (end - p < 2) {
215         ALOGE("private key truncated");
216         return NULL;
217     }
218     for (size_t i = 0; i < sizeof(type); i++) {
219         privateLen = (privateLen << 8) | *p++;
220     }
221     if (p + privateLen > end) {
222         ALOGE("private key length encoding error: size=%ld, end=%td", privateLen, end - p);
223         return NULL;
224     }
225 
226     Unique_EVP_PKEY pkey(EVP_PKEY_new());
227     if (pkey.get() == NULL) {
228         logOpenSSLError("unwrap_key");
229         return NULL;
230     }
231     EVP_PKEY* tmp = pkey.get();
232 
233     if (d2i_PrivateKey(type, &tmp, &p, privateLen) == NULL) {
234         logOpenSSLError("unwrap_key");
235         return NULL;
236     }
237 
238     return pkey.release();
239 }
240 
generate_dsa_keypair(EVP_PKEY * pkey,const keymaster_dsa_keygen_params_t * dsa_params)241 static int generate_dsa_keypair(EVP_PKEY* pkey, const keymaster_dsa_keygen_params_t* dsa_params) {
242     if (dsa_params->key_size < 512) {
243         ALOGI("Requested DSA key size is too small (<512)");
244         return -1;
245     }
246 
247     Unique_DSA dsa(DSA_new());
248 
249     if (dsa_params->generator_len == 0 || dsa_params->prime_p_len == 0 ||
250         dsa_params->prime_q_len == 0 || dsa_params->generator == NULL ||
251         dsa_params->prime_p == NULL || dsa_params->prime_q == NULL) {
252         if (DSA_generate_parameters_ex(dsa.get(), dsa_params->key_size, NULL, 0, NULL, NULL,
253                                        NULL) != 1) {
254             logOpenSSLError("generate_dsa_keypair");
255             return -1;
256         }
257     } else {
258         dsa->g = BN_bin2bn(dsa_params->generator, dsa_params->generator_len, NULL);
259         if (dsa->g == NULL) {
260             logOpenSSLError("generate_dsa_keypair");
261             return -1;
262         }
263 
264         dsa->p = BN_bin2bn(dsa_params->prime_p, dsa_params->prime_p_len, NULL);
265         if (dsa->p == NULL) {
266             logOpenSSLError("generate_dsa_keypair");
267             return -1;
268         }
269 
270         dsa->q = BN_bin2bn(dsa_params->prime_q, dsa_params->prime_q_len, NULL);
271         if (dsa->q == NULL) {
272             logOpenSSLError("generate_dsa_keypair");
273             return -1;
274         }
275     }
276 
277     if (DSA_generate_key(dsa.get()) != 1) {
278         logOpenSSLError("generate_dsa_keypair");
279         return -1;
280     }
281 
282     if (EVP_PKEY_assign_DSA(pkey, dsa.get()) == 0) {
283         logOpenSSLError("generate_dsa_keypair");
284         return -1;
285     }
286     release_because_ownership_transferred(dsa);
287 
288     return 0;
289 }
290 
generate_ec_keypair(EVP_PKEY * pkey,const keymaster_ec_keygen_params_t * ec_params)291 static int generate_ec_keypair(EVP_PKEY* pkey, const keymaster_ec_keygen_params_t* ec_params) {
292     Unique_EC_GROUP group;
293     switch (ec_params->field_size) {
294     case 192:
295         group.reset(EC_GROUP_new_by_curve_name(NID_X9_62_prime192v1));
296         break;
297     case 224:
298         group.reset(EC_GROUP_new_by_curve_name(NID_secp224r1));
299         break;
300     case 256:
301         group.reset(EC_GROUP_new_by_curve_name(NID_X9_62_prime256v1));
302         break;
303     case 384:
304         group.reset(EC_GROUP_new_by_curve_name(NID_secp384r1));
305         break;
306     case 521:
307         group.reset(EC_GROUP_new_by_curve_name(NID_secp521r1));
308         break;
309     default:
310         break;
311     }
312 
313     if (group.get() == NULL) {
314         logOpenSSLError("generate_ec_keypair");
315         return -1;
316     }
317 
318     EC_GROUP_set_point_conversion_form(group.get(), POINT_CONVERSION_UNCOMPRESSED);
319     EC_GROUP_set_asn1_flag(group.get(), OPENSSL_EC_NAMED_CURVE);
320 
321     /* initialize EC key */
322     Unique_EC_KEY eckey(EC_KEY_new());
323     if (eckey.get() == NULL) {
324         logOpenSSLError("generate_ec_keypair");
325         return -1;
326     }
327 
328     if (EC_KEY_set_group(eckey.get(), group.get()) != 1) {
329         logOpenSSLError("generate_ec_keypair");
330         return -1;
331     }
332 
333     if (EC_KEY_generate_key(eckey.get()) != 1 || EC_KEY_check_key(eckey.get()) < 0) {
334         logOpenSSLError("generate_ec_keypair");
335         return -1;
336     }
337 
338     if (EVP_PKEY_assign_EC_KEY(pkey, eckey.get()) == 0) {
339         logOpenSSLError("generate_ec_keypair");
340         return -1;
341     }
342     release_because_ownership_transferred(eckey);
343 
344     return 0;
345 }
346 
generate_rsa_keypair(EVP_PKEY * pkey,const keymaster_rsa_keygen_params_t * rsa_params)347 static int generate_rsa_keypair(EVP_PKEY* pkey, const keymaster_rsa_keygen_params_t* rsa_params) {
348     Unique_BIGNUM bn(BN_new());
349     if (bn.get() == NULL) {
350         logOpenSSLError("generate_rsa_keypair");
351         return -1;
352     }
353 
354     if (BN_set_word(bn.get(), rsa_params->public_exponent) == 0) {
355         logOpenSSLError("generate_rsa_keypair");
356         return -1;
357     }
358 
359     /* initialize RSA */
360     Unique_RSA rsa(RSA_new());
361     if (rsa.get() == NULL) {
362         logOpenSSLError("generate_rsa_keypair");
363         return -1;
364     }
365 
366     if (!RSA_generate_key_ex(rsa.get(), rsa_params->modulus_size, bn.get(), NULL) ||
367         RSA_check_key(rsa.get()) < 0) {
368         logOpenSSLError("generate_rsa_keypair");
369         return -1;
370     }
371 
372     if (EVP_PKEY_assign_RSA(pkey, rsa.get()) == 0) {
373         logOpenSSLError("generate_rsa_keypair");
374         return -1;
375     }
376     release_because_ownership_transferred(rsa);
377 
378     return 0;
379 }
380 
openssl_generate_keypair(const keymaster_device_t *,const keymaster_keypair_t key_type,const void * key_params,uint8_t ** keyBlob,size_t * keyBlobLength)381 __attribute__((visibility("default"))) int openssl_generate_keypair(
382     const keymaster_device_t*, const keymaster_keypair_t key_type, const void* key_params,
383     uint8_t** keyBlob, size_t* keyBlobLength) {
384     Unique_EVP_PKEY pkey(EVP_PKEY_new());
385     if (pkey.get() == NULL) {
386         logOpenSSLError("openssl_generate_keypair");
387         return -1;
388     }
389 
390     if (key_params == NULL) {
391         ALOGW("key_params == null");
392         return -1;
393     } else if (key_type == TYPE_DSA) {
394         const keymaster_dsa_keygen_params_t* dsa_params =
395             (const keymaster_dsa_keygen_params_t*)key_params;
396         generate_dsa_keypair(pkey.get(), dsa_params);
397     } else if (key_type == TYPE_EC) {
398         const keymaster_ec_keygen_params_t* ec_params =
399             (const keymaster_ec_keygen_params_t*)key_params;
400         generate_ec_keypair(pkey.get(), ec_params);
401     } else if (key_type == TYPE_RSA) {
402         const keymaster_rsa_keygen_params_t* rsa_params =
403             (const keymaster_rsa_keygen_params_t*)key_params;
404         generate_rsa_keypair(pkey.get(), rsa_params);
405     } else {
406         ALOGW("Unsupported key type %d", key_type);
407         return -1;
408     }
409 
410     if (wrap_key(pkey.get(), EVP_PKEY_type(pkey->type), keyBlob, keyBlobLength)) {
411         return -1;
412     }
413 
414     return 0;
415 }
416 
openssl_import_keypair(const keymaster_device_t *,const uint8_t * key,const size_t key_length,uint8_t ** key_blob,size_t * key_blob_length)417 __attribute__((visibility("default"))) int openssl_import_keypair(const keymaster_device_t*,
418                                                                   const uint8_t* key,
419                                                                   const size_t key_length,
420                                                                   uint8_t** key_blob,
421                                                                   size_t* key_blob_length) {
422     if (key == NULL) {
423         ALOGW("input key == NULL");
424         return -1;
425     } else if (key_blob == NULL || key_blob_length == NULL) {
426         ALOGW("output key blob or length == NULL");
427         return -1;
428     }
429 
430     Unique_PKCS8_PRIV_KEY_INFO pkcs8(d2i_PKCS8_PRIV_KEY_INFO(NULL, &key, key_length));
431     if (pkcs8.get() == NULL) {
432         logOpenSSLError("openssl_import_keypair");
433         return -1;
434     }
435 
436     /* assign to EVP */
437     Unique_EVP_PKEY pkey(EVP_PKCS82PKEY(pkcs8.get()));
438     if (pkey.get() == NULL) {
439         logOpenSSLError("openssl_import_keypair");
440         return -1;
441     }
442     release_because_ownership_transferred(pkcs8);
443 
444     if (wrap_key(pkey.get(), EVP_PKEY_type(pkey->type), key_blob, key_blob_length)) {
445         return -1;
446     }
447 
448     return 0;
449 }
450 
openssl_get_keypair_public(const struct keymaster_device *,const uint8_t * key_blob,const size_t key_blob_length,uint8_t ** x509_data,size_t * x509_data_length)451 __attribute__((visibility("default"))) int openssl_get_keypair_public(
452     const struct keymaster_device*, const uint8_t* key_blob, const size_t key_blob_length,
453     uint8_t** x509_data, size_t* x509_data_length) {
454 
455     if (x509_data == NULL || x509_data_length == NULL) {
456         ALOGW("output public key buffer == NULL");
457         return -1;
458     }
459 
460     Unique_EVP_PKEY pkey(unwrap_key(key_blob, key_blob_length));
461     if (pkey.get() == NULL) {
462         return -1;
463     }
464 
465     int len = i2d_PUBKEY(pkey.get(), NULL);
466     if (len <= 0) {
467         logOpenSSLError("openssl_get_keypair_public");
468         return -1;
469     }
470 
471     UniquePtr<uint8_t, Malloc_Free> key(static_cast<uint8_t*>(malloc(len)));
472     if (key.get() == NULL) {
473         ALOGE("Could not allocate memory for public key data");
474         return -1;
475     }
476 
477     unsigned char* tmp = reinterpret_cast<unsigned char*>(key.get());
478     if (i2d_PUBKEY(pkey.get(), &tmp) != len) {
479         logOpenSSLError("openssl_get_keypair_public");
480         return -1;
481     }
482 
483     ALOGV("Length of x509 data is %d", len);
484     *x509_data_length = len;
485     *x509_data = key.release();
486 
487     return 0;
488 }
489 
sign_dsa(EVP_PKEY * pkey,keymaster_dsa_sign_params_t * sign_params,const uint8_t * data,const size_t dataLength,uint8_t ** signedData,size_t * signedDataLength)490 static int sign_dsa(EVP_PKEY* pkey, keymaster_dsa_sign_params_t* sign_params, const uint8_t* data,
491                     const size_t dataLength, uint8_t** signedData, size_t* signedDataLength) {
492     if (sign_params->digest_type != DIGEST_NONE) {
493         ALOGW("Cannot handle digest type %d", sign_params->digest_type);
494         return -1;
495     }
496 
497     Unique_DSA dsa(EVP_PKEY_get1_DSA(pkey));
498     if (dsa.get() == NULL) {
499         logOpenSSLError("openssl_sign_dsa");
500         return -1;
501     }
502 
503     unsigned int dsaSize = DSA_size(dsa.get());
504     UniquePtr<uint8_t, Malloc_Free> signedDataPtr(reinterpret_cast<uint8_t*>(malloc(dsaSize)));
505     if (signedDataPtr.get() == NULL) {
506         logOpenSSLError("openssl_sign_dsa");
507         return -1;
508     }
509 
510     unsigned char* tmp = reinterpret_cast<unsigned char*>(signedDataPtr.get());
511     if (DSA_sign(0, data, dataLength, tmp, &dsaSize, dsa.get()) <= 0) {
512         logOpenSSLError("openssl_sign_dsa");
513         return -1;
514     }
515 
516     *signedDataLength = dsaSize;
517     *signedData = signedDataPtr.release();
518 
519     return 0;
520 }
521 
sign_ec(EVP_PKEY * pkey,keymaster_ec_sign_params_t * sign_params,const uint8_t * data,const size_t dataLength,uint8_t ** signedData,size_t * signedDataLength)522 static int sign_ec(EVP_PKEY* pkey, keymaster_ec_sign_params_t* sign_params, const uint8_t* data,
523                    const size_t dataLength, uint8_t** signedData, size_t* signedDataLength) {
524     if (sign_params->digest_type != DIGEST_NONE) {
525         ALOGW("Cannot handle digest type %d", sign_params->digest_type);
526         return -1;
527     }
528 
529     Unique_EC_KEY eckey(EVP_PKEY_get1_EC_KEY(pkey));
530     if (eckey.get() == NULL) {
531         logOpenSSLError("openssl_sign_ec");
532         return -1;
533     }
534 
535     unsigned int ecdsaSize = ECDSA_size(eckey.get());
536     UniquePtr<uint8_t, Malloc_Free> signedDataPtr(reinterpret_cast<uint8_t*>(malloc(ecdsaSize)));
537     if (signedDataPtr.get() == NULL) {
538         logOpenSSLError("openssl_sign_ec");
539         return -1;
540     }
541 
542     unsigned char* tmp = reinterpret_cast<unsigned char*>(signedDataPtr.get());
543     if (ECDSA_sign(0, data, dataLength, tmp, &ecdsaSize, eckey.get()) <= 0) {
544         logOpenSSLError("openssl_sign_ec");
545         return -1;
546     }
547 
548     *signedDataLength = ecdsaSize;
549     *signedData = signedDataPtr.release();
550 
551     return 0;
552 }
553 
sign_rsa(EVP_PKEY * pkey,keymaster_rsa_sign_params_t * sign_params,const uint8_t * data,const size_t dataLength,uint8_t ** signedData,size_t * signedDataLength)554 static int sign_rsa(EVP_PKEY* pkey, keymaster_rsa_sign_params_t* sign_params, const uint8_t* data,
555                     const size_t dataLength, uint8_t** signedData, size_t* signedDataLength) {
556     if (sign_params->digest_type != DIGEST_NONE) {
557         ALOGW("Cannot handle digest type %d", sign_params->digest_type);
558         return -1;
559     } else if (sign_params->padding_type != PADDING_NONE) {
560         ALOGW("Cannot handle padding type %d", sign_params->padding_type);
561         return -1;
562     }
563 
564     Unique_RSA rsa(EVP_PKEY_get1_RSA(pkey));
565     if (rsa.get() == NULL) {
566         logOpenSSLError("openssl_sign_rsa");
567         return -1;
568     }
569 
570     UniquePtr<uint8_t, Malloc_Free> signedDataPtr(reinterpret_cast<uint8_t*>(malloc(dataLength)));
571     if (signedDataPtr.get() == NULL) {
572         logOpenSSLError("openssl_sign_rsa");
573         return -1;
574     }
575 
576     unsigned char* tmp = reinterpret_cast<unsigned char*>(signedDataPtr.get());
577     if (RSA_private_encrypt(dataLength, data, tmp, rsa.get(), RSA_NO_PADDING) <= 0) {
578         logOpenSSLError("openssl_sign_rsa");
579         return -1;
580     }
581 
582     *signedDataLength = dataLength;
583     *signedData = signedDataPtr.release();
584 
585     return 0;
586 }
587 
openssl_sign_data(const keymaster_device_t *,const void * params,const uint8_t * keyBlob,const size_t keyBlobLength,const uint8_t * data,const size_t dataLength,uint8_t ** signedData,size_t * signedDataLength)588 __attribute__((visibility("default"))) int openssl_sign_data(
589     const keymaster_device_t*, const void* params, const uint8_t* keyBlob,
590     const size_t keyBlobLength, const uint8_t* data, const size_t dataLength, uint8_t** signedData,
591     size_t* signedDataLength) {
592     if (data == NULL) {
593         ALOGW("input data to sign == NULL");
594         return -1;
595     } else if (signedData == NULL || signedDataLength == NULL) {
596         ALOGW("output signature buffer == NULL");
597         return -1;
598     }
599 
600     Unique_EVP_PKEY pkey(unwrap_key(keyBlob, keyBlobLength));
601     if (pkey.get() == NULL) {
602         return -1;
603     }
604 
605     int type = EVP_PKEY_type(pkey->type);
606     if (type == EVP_PKEY_DSA) {
607         const keymaster_dsa_sign_params_t* sign_params =
608             reinterpret_cast<const keymaster_dsa_sign_params_t*>(params);
609         return sign_dsa(pkey.get(), const_cast<keymaster_dsa_sign_params_t*>(sign_params), data,
610                         dataLength, signedData, signedDataLength);
611     } else if (type == EVP_PKEY_EC) {
612         const keymaster_ec_sign_params_t* sign_params =
613             reinterpret_cast<const keymaster_ec_sign_params_t*>(params);
614         return sign_ec(pkey.get(), const_cast<keymaster_ec_sign_params_t*>(sign_params), data,
615                        dataLength, signedData, signedDataLength);
616     } else if (type == EVP_PKEY_RSA) {
617         const keymaster_rsa_sign_params_t* sign_params =
618             reinterpret_cast<const keymaster_rsa_sign_params_t*>(params);
619         return sign_rsa(pkey.get(), const_cast<keymaster_rsa_sign_params_t*>(sign_params), data,
620                         dataLength, signedData, signedDataLength);
621     } else {
622         ALOGW("Unsupported key type");
623         return -1;
624     }
625 }
626 
verify_dsa(EVP_PKEY * pkey,keymaster_dsa_sign_params_t * sign_params,const uint8_t * signedData,const size_t signedDataLength,const uint8_t * signature,const size_t signatureLength)627 static int verify_dsa(EVP_PKEY* pkey, keymaster_dsa_sign_params_t* sign_params,
628                       const uint8_t* signedData, const size_t signedDataLength,
629                       const uint8_t* signature, const size_t signatureLength) {
630     if (sign_params->digest_type != DIGEST_NONE) {
631         ALOGW("Cannot handle digest type %d", sign_params->digest_type);
632         return -1;
633     }
634 
635     Unique_DSA dsa(EVP_PKEY_get1_DSA(pkey));
636     if (dsa.get() == NULL) {
637         logOpenSSLError("openssl_verify_dsa");
638         return -1;
639     }
640 
641     if (DSA_verify(0, signedData, signedDataLength, signature, signatureLength, dsa.get()) <= 0) {
642         logOpenSSLError("openssl_verify_dsa");
643         return -1;
644     }
645 
646     return 0;
647 }
648 
verify_ec(EVP_PKEY * pkey,keymaster_ec_sign_params_t * sign_params,const uint8_t * signedData,const size_t signedDataLength,const uint8_t * signature,const size_t signatureLength)649 static int verify_ec(EVP_PKEY* pkey, keymaster_ec_sign_params_t* sign_params,
650                      const uint8_t* signedData, const size_t signedDataLength,
651                      const uint8_t* signature, const size_t signatureLength) {
652     if (sign_params->digest_type != DIGEST_NONE) {
653         ALOGW("Cannot handle digest type %d", sign_params->digest_type);
654         return -1;
655     }
656 
657     Unique_EC_KEY eckey(EVP_PKEY_get1_EC_KEY(pkey));
658     if (eckey.get() == NULL) {
659         logOpenSSLError("openssl_verify_ec");
660         return -1;
661     }
662 
663     if (ECDSA_verify(0, signedData, signedDataLength, signature, signatureLength, eckey.get()) <=
664         0) {
665         logOpenSSLError("openssl_verify_ec");
666         return -1;
667     }
668 
669     return 0;
670 }
671 
verify_rsa(EVP_PKEY * pkey,keymaster_rsa_sign_params_t * sign_params,const uint8_t * signedData,const size_t signedDataLength,const uint8_t * signature,const size_t signatureLength)672 static int verify_rsa(EVP_PKEY* pkey, keymaster_rsa_sign_params_t* sign_params,
673                       const uint8_t* signedData, const size_t signedDataLength,
674                       const uint8_t* signature, const size_t signatureLength) {
675     if (sign_params->digest_type != DIGEST_NONE) {
676         ALOGW("Cannot handle digest type %d", sign_params->digest_type);
677         return -1;
678     } else if (sign_params->padding_type != PADDING_NONE) {
679         ALOGW("Cannot handle padding type %d", sign_params->padding_type);
680         return -1;
681     } else if (signatureLength != signedDataLength) {
682         ALOGW("signed data length must be signature length");
683         return -1;
684     }
685 
686     Unique_RSA rsa(EVP_PKEY_get1_RSA(pkey));
687     if (rsa.get() == NULL) {
688         logOpenSSLError("openssl_verify_data");
689         return -1;
690     }
691 
692     UniquePtr<uint8_t[]> dataPtr(new uint8_t[signedDataLength]);
693     if (dataPtr.get() == NULL) {
694         logOpenSSLError("openssl_verify_data");
695         return -1;
696     }
697 
698     unsigned char* tmp = reinterpret_cast<unsigned char*>(dataPtr.get());
699     if (!RSA_public_decrypt(signatureLength, signature, tmp, rsa.get(), RSA_NO_PADDING)) {
700         logOpenSSLError("openssl_verify_data");
701         return -1;
702     }
703 
704     int result = 0;
705     for (size_t i = 0; i < signedDataLength; i++) {
706         result |= tmp[i] ^ signedData[i];
707     }
708 
709     return result == 0 ? 0 : -1;
710 }
711 
openssl_verify_data(const keymaster_device_t *,const void * params,const uint8_t * keyBlob,const size_t keyBlobLength,const uint8_t * signedData,const size_t signedDataLength,const uint8_t * signature,const size_t signatureLength)712 __attribute__((visibility("default"))) int openssl_verify_data(
713     const keymaster_device_t*, const void* params, const uint8_t* keyBlob,
714     const size_t keyBlobLength, const uint8_t* signedData, const size_t signedDataLength,
715     const uint8_t* signature, const size_t signatureLength) {
716 
717     if (signedData == NULL || signature == NULL) {
718         ALOGW("data or signature buffers == NULL");
719         return -1;
720     }
721 
722     Unique_EVP_PKEY pkey(unwrap_key(keyBlob, keyBlobLength));
723     if (pkey.get() == NULL) {
724         return -1;
725     }
726 
727     int type = EVP_PKEY_type(pkey->type);
728     if (type == EVP_PKEY_DSA) {
729         const keymaster_dsa_sign_params_t* sign_params =
730             reinterpret_cast<const keymaster_dsa_sign_params_t*>(params);
731         return verify_dsa(pkey.get(), const_cast<keymaster_dsa_sign_params_t*>(sign_params),
732                           signedData, signedDataLength, signature, signatureLength);
733     } else if (type == EVP_PKEY_RSA) {
734         const keymaster_rsa_sign_params_t* sign_params =
735             reinterpret_cast<const keymaster_rsa_sign_params_t*>(params);
736         return verify_rsa(pkey.get(), const_cast<keymaster_rsa_sign_params_t*>(sign_params),
737                           signedData, signedDataLength, signature, signatureLength);
738     } else if (type == EVP_PKEY_EC) {
739         const keymaster_ec_sign_params_t* sign_params =
740             reinterpret_cast<const keymaster_ec_sign_params_t*>(params);
741         return verify_ec(pkey.get(), const_cast<keymaster_ec_sign_params_t*>(sign_params),
742                          signedData, signedDataLength, signature, signatureLength);
743     } else {
744         ALOGW("Unsupported key type %d", type);
745         return -1;
746     }
747 }
748